Now a team made up of a geneticist, philosopher and chicken farmer claim to have found an answer. It was the egg.Put simply, the reason is down to the fact that genetic material does not change during an animal's life.
So at some point in time, two creatures which we'd probably say were chickens, and yet were not quite exactly chickens, got together one evening for some cross-species chicken sex, and the result of that happy union was the egg of a chicken.
That's not quite the whole story though. What was required for chickens to become chickens, rather than just mutants of some species they evolved or diverged from, was a 'speciation' event. A bunch of our newly created chickens would wander off from the crowd one day, only be to separated from them, forever by some drastic event. Perhaps they just got lost, or there was a rock fall, volcanic eruption or flood. Whatever happened, a bunch of 'chickens' which were possibly half red junglefowl and half grey junglefowl, did split up and become chickens.
So science says it was the egg!
While scientists had to go the trouble of figuring this all out, biblical scholars merely have to read the bible for the answer. And fortunately their God does deliver on this occasion, almost...
The Bible: Genesis 1:20-22
Then God said, “Let the waters abound with an abundance of living creatures, and let birds fly above the earth across the face of the firmament of the heavens.” 21 So God created great sea creatures and every living thing that moves, with which the waters abounded, according to their kind, and every winged bird according to its kind. And God saw that it was good. 22 And God blessed them, saying, “Be fruitful and multiply, and fill the waters in the seas, and let birds multiply on the earth.”
So it sounds like, from the text, like he didn't just put a bunch of bird eggs on the Earth and wait for them to hatch. That would have been, well, boring. Far more God-like is it not, for them to just suddenly appear, mid-flight? Hopefully these newly created birds knew how to fly already. It would have been an unhappy day if they all plummeted to the ground and died.
But actually, if I did look to the bible to confirm anything, I'd be a bit disappointed by this, since it doesn't explicitly state that he didn't just leave the chicken eggs lying around and wait for them to hatch. It just makes it seem likely. Oh well.